Character mistake: When Vivian is in the tub singing "KISS" by Prince, she sings the verses in the wrong order. Not a big mistake, but a noticeable one for a Prince fan.
Deliberate mistake: In the hotel bar at night, when Edward is playing the piano and Vivian goes to find him, after Edward has dismissed everyone else from the room Vivian sits on top of the piano and puts her feet on the keyboard. Her feet go onto the keys in the middle of the keyboard but the sound that comes out is from the bottom and the top notes of the piano.
Continuity mistake: Vivian's hair style changes frequently from the point when the necklace is given to her to the end of the night at the opera.
Other mistake: As the hotel manager is going over table manners with Vivian, when he picks up the salad fork he says salad forks have 3 tines, but when he puts that fork back on the table you can see it has 4.
Continuity mistake: In the scene where Jason Alexander is talking to Richard Gere (on his early-90's cell phone), the pen on the desk in front of Alexander shifts positions between two shots, even though he's sitting with his hands away from the desk at that part of the conversation. (01:00:45)
Continuity mistake: When Vivian is eating dinner and the snail "flies" away from her, it goes to the far right of the screen disappearing. Then in the next shot the waiter catches it, but it flew too far to the right for him to catch it.
Continuity mistake: When Edward and Vivian kiss for the first time, her white nightgown goes from being long to being short.
Continuity mistake: In the screen where Vivian has been on the shopping spree, she returns to the hotel wearing the cream colored dress and a black hat. When she walks into the hotel, her black purse is under one arm. Then they show a behind shot of her walking away and the purse is under the other arm.
Continuity mistake: At the beginning when Vivian is sitting on his desk she says " you can pay me now" and he hands her her money and she puts it inside her boot. Later, after the Champagne comes and she is sitting on the steps in the hotel room she asks "do you mind if I take off my boots." When she does there is no money, not even in the knee highs she is wearing under her boots.
Visible crew/equipment: After the failed shopping trip, the manager takes Vivian to his office, and lifts a chrome pot to water the plant. The film crew can be seen in the reflection on the pot. (00:42:40)
Answer: As the other answer indicated, it was part of her cheap hooker persona, but it also makes a greater impact on the audience when they see Vivian undergo her "transformation" with the classy designer clothes, toned-down make-up, and her own nicely-styled hair.
raywest ★